As part of the inquiry, Congress and the Justice Department are looking at Russia's interference in the 2016 election, as well as whether Trump or his associates knew or participated in the Kremlin's attempts to undermine the race.

So far, Flynn and Papadopoulos have pleaded guilty to making false statements to investigators about their contacts with Russia, and Manafort and Gates have pleaded not guilty to 12 counts related to financial crimes and their work with foreign governments.

The calendar below includes information about all known events and ties between members of the Trump campaign and Russia.

It also includes claims of collusion between the campaign and Russia that were documented in the Steele dossier, an explosive collection of memos compiled by former British spy Christopher Steele. Those allegations are largely uncorroborated, but many events have been confirmed since it was published in January 2017.

Here's everything we know so far about the Trump campaign's ties to the Kremlin and how Russia meddled in the election: